A paper-folding machine of this class has been known (Swiss Patent No. 390,287), in which the pivoted levers, on which the folding rollers are mounted, are in spring-like contact with a lever arm at the end of a rod-shaped, axially movably mounted contact element, whose other end is in liftable contact with the front surface of an adjusting means. This adjusting means is designed as a threaded bolt, which can be adjustably screwed into a threaded bore of a bearing part, which threaded bore is coaxial with the axis of the contact element. To set the actually desired folding gap width, small plates, whose thickness corresponds to the folding gap width to be set, are placed as intermediate layers between the contact element and the front face of the threaded bolt facing the contact element. The threaded bolt, which is provided with a turning, serves only for correcting adjustment of the contact element, in order to finely adjust the folding gap width set with the intermediate layers upward or downward corresponding to the other properties of the paper.
In this and other prior-art paper-folding machines of this class, the distances between the axes of the folding roller pairs folding the individual folding stations can be adjusted only manually, after the user determined the number of paper layers in which the paper being folded will pass through the individual folding stations. This may be done on the basis of the paper thickness known or determined, as well as on the basis of the type of folding set. However, it should be considered that all folding stations, which will also be passed through by a trailing, one-layer folding material section, can be set only to the thickness of a single layer of paper, because otherwise the frictional drive required for folding this folding material section trailing as a single layer would no longer be guaranteed.
A considerably greater accuracy of the folding operation can be achieved when the distances between the folding rollers forming in pairs one folding station are set to a folding gap width that corresponds to the value determined by the paper thickness and the number of layers with which the material being folded passes through the folding station in question. Accordingly, it is important to make it possible to set every individual folding station to the corresponding folding gap width. However, it is difficult to accomplish this task according to the prior-art, manual method, because an average person skilled in the art, to whom only the type of folding, the paper thickness, and possibly the paper length of the initial format are known, has a difficult time determining the correct folding gap width of every individual folding station. Correspondingly, such incorrect settings are also frequent on such folding machines in practice.